Glucose transport in a murine mammary epithelial cell line.

The glucose transport systems of the COMMA-D cell line (a murine mammary epithelial cell line) were examined using 2-deoxyglucose as substrate. The kinetics and inhibition studies with other sugars including xylose suggested that the transport system had properties of both GLUT-1 and Glut-3. Subsequent analysis of mRNA transcripts using cDNAs for GLUT-I to 4 showed that only GLUT-1 was expressed in the COMMA-D cells. The results highlight the fact that kinetic and substrate specificity are not sufficient, by themselves, for the identification and characterisation of GLUT isoforms in cultured cells.